The present invention relates to a transferring body apparatus installed in a copying machine as an application of a color electronic photograph or a printer.
There are various types of printing methods for use in a color electronic copying machine, one of which is a method of overlapping toner images in colors on a photosensitive body, or an intermediate transferring body, or a sheet.
According to the method of overlapping toner images in colors on a photosensitive body, exposing needs to be performed on toner images, and thus a considerable problem will occur in image quality.
According to the method of overlapping toner images on an intermediate transferring body, two transfer steps are needed: a primary transfer step for transferring a toner image from a photosensitive body to the intermediate transferring body; and a secondary transfer step for transferring a toner image from the intermediate transferring body to a sheet.
According to the method of overlapping toner images on a sheet, a toner image is transferred from a photosensitive body directly to the sheet, and thus the primary and secondary transfer steps as needed for the intermediate transferring body method do not need to be performed. Therefore, this method has been generally employed in various color copying machines.
On the other hand, the intermediate transferring body method is thought to be unsuitable if a high quality image is desired. This method is, however, advantageous in space efficiency since the intermediate transferring body can be formed in a belt, or a thick sheet, and thus employed in a machine such as a color printer for which the image quality is not the highest priority.
The intermediate transferring body can be formed in a form other than a belt, for example, in a drum. The intermediate transferring body formed in a drum (hereinafter referred to as xe2x80x9cthe intermediate transferring drumxe2x80x9d) is formed by covering a surface of a metal drum with a rubber belt. If the rubber belt slips over the metal drum, the toner images shift from each other, or the rubber belt twists to rise, which causes a trouble in an image transfer or results in an uneven image transfer. Especially, when the intermediate transferring body has no driving source, a large force will be applied to the surface of the intermediate transferring body in the driving of a photosensitive body.
Even if the driving means for driving the intermediate transferring body at a speed equal to that of the photosensitive body, when a blade contacting the intermediate transferring body is used as a cleaner of the intermediate transferring body, a large load is applied to the rubber belt, thereby the rubber belt may slip or shift.
In order to prevent slippage between the metal drum and the rubber belt, an adhesive agent is filled between the metal drum and the rubber belt when the metal drum is covered with the rubber belt.
In using the adhesive agent, however, if the adhesive agent is not applied evenly, the surface of the intermediate transferring body is made uneven, thereby uneven image transfer will occur. The yield cannot be increased thereby, and thus mass-production cannot be attained with ease.
If the metal base of the intermediate transferring body can be covered with the rubber belt without any adhesive agent, a uniform transfer and an improvement of the yield can be attained. In order to prevent slippage between the base and the rubber belt without an adhesive agent, the best way is to extend a rubber belt having high elasticity to cover the metal base. However, the winding of a very hard rubber belt having a small diameter onto the metal drum will terribly deteriorate the manufacturing efficiency, and thus mass-production cannot be attained.
Even if slippage does not occur between the metal base and the rubber belt in an early stage of use, when the machine is not used for a long period of time, or when the end of the life of the intermediate transfer body is approaching, the rubber belt will become slack, resulting in the slip between the metal base and the rubber belt.
The present invention is made in consideration of the above, and is intended to provide an intermediate transfer body which does not deteriorate the manufacturing efficiency even if the base is covered with an elastic member without an adhesive agent, and prevents the slip between the base and the elastic member for a long period of time.
The transferring body apparatus of the present invention comprises a cylindrical base and an elastic member covering the cylindrical base therewith to which an image is transferred, wherein the elastic member has a hardness (JIS-A) of 60 to 80 degrees, a thickness of 0.2-0.8 mm, a tensile stress of 40 kgf/cm2 or more, supposing an outer diameter of the base is R, and an inner diameter of the elastic member is r, 1.03xe2x89xa6R/rxe2x89xa61.15 is satisfied, and supposing a surface roughness of the outer surface of the base is S1 xcexcm Rz, and a surface roughness of the inner surface of the electric member is S2 xcexcm Rz, S1+S2xe2x89xa612, S1xe2x89xa65 are satisfied.
The transferring body apparatus of the present invention comprises a cylindrical base and an elastic member covering the cylindrical base therewith to which an image is transferred, wherein the elastic member has a hardness (JIS-A) of 60 degrees or less, a thickness of 0.2-0.8 mm, a tensile stress of 40 kgf/cm2 or more, supposing an outer diameter of the base member is R, and an inner diameter of the elastic member is r, 1.03xe2x89xa6R/rxe2x89xa61.15 is satisfied, and supposing a surface roughness of the outer surface of the base is S1 xcexcm Rz, and a surface roughness of the inner surface of the elastic member is S2 xcexcm Rz, S1+S2xe2x89xa630, S1xe2x89xa610 are satisfied.
The transferring body apparatus of the present invention comprises a cylindrical base and an elastic member covering the cylindrical base therewith to which an image is transferred, wherein the elastic member has a hardness (JIS-A) of 80 degrees or less, a thickness of 0.2-0.8 mm, a tensile stress of 40 kgf/cm2 or more, supposing an outer diameter of the base is R, and an inner diameter of the elastic member is r, 1.03xe2x89xa6R/rxe2x89xa61.15 is satisfied, and supposing a surface roughness of the outer surface of the base is S1 xcexcm Rz, and a surface roughness of the inner surface of the elastic member is S2 xcexcm Rz, S1+S2xe2x89xa630, S1xe2x89xa610 are satisfied.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.